Distributed Renewable Energy Operating Impacts and Valuation Study

Section 1
Solar Hot Water Heating Systems
Solar hot water (SHW) heating is a distributed solar application designed to reduce load from
residential domestic hot water heating. It is applicable to residential customers only and
incentives are offered to customers on a first year dollar per kilowatt hour ($/kWh) basis (the
incentives are designed to be a one-time “up-front” payment). Table 1-3 shows the current
schedule of rebate offerings.
Table 1-3
Residential Solar Hot Water Rebates
APS Rebates $/kWh 2008 2009 2010 2011 2012 2013
Residential SHW $0.750 $0.750 $0.675 $0.675 $0.574 $0.574
_____
Source: APS
Note: The incentives are for first year energy savings only and are a one-time, “up-front” payment.
As of the end of 2008, there were 1,076 SHW systems installed in the APS service territory. Of
this total, more than one-third (376) were installed in 2008 (annualized basis), suggesting a rapid
increase in adoption of these systems. Figure 1-6 presents the number of SHW installations by
year.
Figure 1-6: Number of SHW Installations by Year
Number of Systems
400
350
300
250
200
150
100
50
0
2002 2003 2004 2005 2006 2007 2008
Year
_____
Source: APS Data
Note: 2008 value is annualized based on 11½ months of data.
1-8 R. W. Beck, Inc. Arizona Public Service